An alternator is typically utilized to provide a direct current (DC) output and to maintain the electrical charge on a battery. A conventional motor vehicle alternator includes a three phase stator winding with a rotor magnetically coupled to the stator and driven by the vehicle's internal combustion engine. As the rotor is driven, three phase current generated at the output connections of the stator windings is rectified by a three phase diode rectifier. The output current and efficiency of the alternator vary with the speed of the engine which is controlled in accordance with the operational requirements of the vehicle. At low and high speeds, the alternator output may be insufficient to provide the power needed to operate some or all of the electrical equipment of the vehicle. Also at high speeds, the efficiency, or economy, of the alternator may not be maximized.
Accordingly, there is a need for increasing the output current and/or efficiency of the alternator without increasing the volume or weight of the alternator.